Hey folks - I'm having issues getting a docker agent to run flows locally. I'm using prefect cloud - I have confirmed that I can run a non-docker flow locally - and trigger it from the cloud UI (so

backend

is correctly set and the runner token is available as an environment variable). however, when I give the flow docker storage and spin up a docker agent, nothing happens when I try to trigger a flow from the ui - no errors, it's just like it's not receiving any instructions from prefect cloud. I am working in WSL2 (widows linux subsystem) - which creates all kinds of hellish networking issues (classic windows) - but I've confirmed that docker is working and I've run the docker image that was created for my flow and run the flow manually within the container by unpickling and running

flow.run

The on thing I thought it might be was failure to connect to the docker daemon (in case wsl ran it somewhere else) but I've confirmed that it's running at unix:///var/run/docker.sock (I think earlier versions of WSL had an issue but I don't think that's what's going on). What else could I try? any suggestions?

prefect diagnostics

output:

{
  "config_overrides": {
    "cloud": {
      "agent": {
        "auth_token": true
      }
    },
    "context": {
      "secrets": false
    }
  },
  "env_vars": [
    "PREFECT__CLOUD__AGENT__AUTH_TOKEN"
  ],
  "system_information": {
    "platform": "Linux-4.19.104-microsoft-standard-x86_64-with-glibc2.29",
    "prefect_version": "0.13.4",
    "python_version": "3.8.1"
  }
}

Hi @Chris Goddard - do your flows enter a

Scheduled

State in the UI but never leave it? Or do they get

Submitted

?

yeah I think they just stay in

Scheduled

and then I get a message saying they're behind schedule - so they never run

Got it! The first thing to check is that the labels on your flow and agent are matching. All the labels your flow has need to exist on your agent as well.

oh - I didn't know that was a consideration - let me try that

Oh interesting, I’ve not seen that before. It looks like your agent isn’t able to communicate with the docker daemon

hmm. it could well be wsl related. it has all kinds of trouble with localhost. because... microsoft.

Yeah that sounds viable. Glad to help!

Sorry @nicholas - this is my own ignorance with docker but do you know how to find out where docker's base url is. docker is working - but wsl has some funky setup with docker and unfortunately all my searching only finds other people with similar problems but no resolution. I see reference to "host.docker.internal" - but I don't know how/where to find that

Hm not off the top of my head but I think there’s a configuration file somewhere that’ll have it. Sorry I’m not super familiar with the windows environment ☹️

haha - neither. definitely not my choice :S

Oh! You have a docker desktop app, right?

yeah

I think there’s a setting for wsl to expose the daemon at a local host location

Oh yup, they’ve got that in the manual 😆

no - at least, so far. one thing with windows is you never know if it's actually not working or you're just supposed to restart something to get it to work (I hate windows so much)

Unfortunately I’m not sure either /:

that's ok

Oh that’s great! I’m glad it turned out to be something simple 😃